Every year, the trees on the Rice campus produce a large amount of leaf debris.
The leaf litter accumulates over drain inlets, especially after a heavy rain or at times when the campus trees are losing their foliage. The picture shows a drain, marked by a stake, to be under at least 4" of leaf debris.
Because the sheet flow of the storm water runoff carries the wet leaves and deposits them, the leaves form a dense mat that does not permit water to flow through the inlet.
Where the leaves do enter the storm sewer system, they become trapped in the inlets or along the storm sewer lines. This prevents some drains, like this one near O'Connor House, from taking water.
Some storm sewer inlets are very small, making them prone to being quickly
covered by grass or leaves in a moderate to heavy rain.
Problem 2: Dysfunctional Drains